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alkej-194
Prediction of Oxygen Mass Transfer Coefficients in Stirred Bioreactor with Rushton Turbine Impeller for Simulated (Non-Microbial) Medias
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 Abstract

The study of oxygen mass transfer was conducted in a laboratory scale 5 liter stirred bioreactor equipped with one Rushton turbine impeller. The effects of superficial gas velocity, impeller speed, power input and liquid viscosity on the oxygen mass transfer were considered. Air/ water and air/CMC systems were used as a liquid media for this study. The concentration of CMC was ranging from 0.5 to 3 w/v. The experimental results show that volumetric oxygen mass transfer coefficient increases with the increase in the superficial gas velocity and impeller speed and decreases with increasing liquid viscosity. The experimental results of kla were correlated with a mathematical correlation describing the influences of the considered factors (the overall power input and the superficial gas velocity) over the studied rages. The predicted kla values give acceptable results compared with the experimental values. The following correlations were obtained:

Air/water system

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Publication Date
Sat Apr 03 2021
Journal Name
Lubricants
UV-Visible Spectrophotometer for Distinguishing Oxidation Time of Engine Oil
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Samples of gasoline engine oil (SAE 5W20) that had been exposed to various oxidation times were inspected with a UV-Visible (UV-Vis) spectrophotometer to select the best wavelengths and wavelength ranges for distinguishing oxidation times. Engine oil samples were subjected to different thermal oxidation periods of 0, 24, 48, 72, 96, 120, and 144 hours, resulting in a range of total base number (TBN) levels. Each wavelength (190.5 – 849.5 nm) and selected wavelength ranges were evaluated to determine the wavelength or wavelength ranges that could best distinguish among all oxidation times. The best wavelengths and wavelength ranges were analyzed with linear regression to determine the best wavelength or range to predict oxidation t

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Publication Date
Mon Jun 04 2018
Journal Name
Baghdad Science Journal
Fabricated of Cu Doped ZnO Nanoparticles for Solar Cell Application
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Copper with different concentrations doped with zinc oxide nanoparticles were prepared from a mixture of zinc acetate and copper acetate with sodium hydroxide in aqueous solution. The structure of the prepared samples was done by X-ray diffraction, atomic force microscopy (AFM) and UV-VIS absorption spectrophotometer. Debye-Scherer formula was used to calculate the size of the prepared samples. The band gap of the nanoparticle ZnO was determined by using UV-VIS optical spectroscopy.

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Publication Date
Tue Nov 01 2022
Journal Name
Japanese Dental Science Review
Pathogenesis of periodontitis – A potential role for epithelial-mesenchymal transition
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Publication Date
Tue May 01 2018
Journal Name
Journal Of Engineering
Design of an Optimal Integral Backstepping Controller for a Quadcopter
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In this paper, an Integral Backstepping Controller (IBC) is designed and optimized for full control, of rotational and translational dynamics, of an unmanned Quadcopter (QC). Before designing the controller, a mathematical model for the QC is developed in a form appropriate for the IBC design. Due to the underactuated property of the QC, it is possible to control the QC Cartesian positions (X, Y, and Z) and the yaw angle through ordering the desired values for them. As for the pitch and roll angles, they are generated by the position controllers. Backstepping Controller (BC) is a practical nonlinear control scheme based on Lyapunov design approach, which can, therefore, guarantee the convergence of the position tracking

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Publication Date
Wed Jul 29 2020
Journal Name
Iraqi Journal Of Science
A Descent Modification of Conjugate Gradient Method for Optimization Models
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In this paper, we suggest a descent modification of the conjugate gradient method which converges globally provided that the exact minimization condition is satisfied. Preliminary numerical experiments on some benchmark problems show that the method is efficient and promising.  

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Publication Date
Fri Dec 03 2021
Journal Name
2021 4th International Conference On Advanced Communication Technologies And Networking (commnet)
Methodology for Predicting the Optimum Design of Radio-Electronic Devices
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Publication Date
Fri Dec 20 2024
Journal Name
Journal Of College Of Law For Legal And Political Sciences
Management's responsibility for breach of investment administrative contracts
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Publication Date
Tue Mar 30 2021
Journal Name
College Of Islamic Sciences
Abu Izac Al-Zauali (d.616 A.H) His life and what Existed of his poetry
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   The aim of this research is to identify the Andalusia  poet  Abu Izac Al-Zauali , whose  most of his poetry and biography had been lost, as well as many Andalusia  poets. So this research is hoped to be the first step to shed the light on the poet’s life and poetry  and to document his poetry as other  writers do. It is also hoped that this research would pave the way , God willing , to the steps of finding more references about this poet .

Key Words: (Al-Zauali, Cordoba, Al-Ruaini choices, Andalusia Poetry , Almuahdi Era).

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Publication Date
Sun Jul 07 2013
Journal Name
Journal Of Educational And Psychological Researches
knowledge management and managers have a primary school principals from the standpoint of their assistants
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knowledge management and managers have a primary school principals from the standpoint of their assistants M . Dr. Suad Vegetables Abbas Research problem: The administration school require a leader administratively The efficiency and skills of management and knowledge to make it effective in the administration follows the scientific method and knowledge of those who through administrative methods emanating from the trends of modern management in the management of educational , as well as the presence of the leaders of effective management has the knowledge and know-how administrative work and how to deal with others and investment optimized for all of the resources available through the future capable of Orientalism to the extent that ou

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Publication Date
Mon Jun 03 2019
Journal Name
مجلة الجامعة العراقية
Justice in Christianity is descriptive
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Justice is a human values that heavenly religions urged, and made her the fundamentals of individual and social and political life, in Allah almighty sent justice messengers, and sent down his books,as the Earth and the heavens with justice, it is a legal system in which a person takes his dues, which protect the rights of the individual And punish him when committing mistakes, so all religions to achieve chiefly Christianity, the Bible that Allah almighty qualities of Justice, and it is not affected by love or hate, and no factors or percentages, but granted to all who are on earth that despite money and prestige, or what was between them. Of affection or no matter, as well as injustice, whether unjustly or self for others, especially the

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